This program-project requests CORE and implementation support for a broadly based program for the study of mental retardation and related aspects of human development. The scientific base for the program rests upon investigation in three major areas: (a) Genetics and Metabolism, (b) Neuroscience, (c) Behavioral Science, all converging on a fourth area, (d) Clinical Studies of the Human Subject. The methodological and philosophical approaches include the clinical disciplines of pediatrics, neurology, neurosurgery, radiology, psychiatry, psychology, ophthalmology, otology and the basic science disciplines of pathology, physiology, pharmacology and biochemistry. The program is housed in five floors of the Pediatric Sciences Building. The objective of the program is to provide a scientific and clinical base for the better understanding of the factors leading to mental retardation and to apply this information to prevention of the disorder, and management of the mentally handicapped individual.